The influence of crack-orientation distribution on the mechanical properties of pre-cracked brittle media. (1st October 2016)

• Record Type: Journal Article
• Authors: Zeng, Xiaguang; Wei, Yujie
• Is Part Of: International journal of solids and structures. Volume 96(2016)
• Page Start: 64
• Page End: 73
• Publication Date: 2016-10-01
• Subjects: Pre-cracked media -- Crack distribution -- Extended finite element method (XFEM) -- Elastic properties -- Strength; Mechanics, Applied -- Periodicals; Structural analysis (Engineering) -- Periodicals; Elastic solids -- Periodicals; Mécanique appliquée -- Périodiques; Constructions, Théorie des -- Périodiques; Solides élastiques -- Périodiques; Elastic solids; Mechanics, Applied; Structural analysis (Engineering); Periodicals; 624.18
• DOI: 10.1016/j.ijsolstr.2016.06.022
• Languages: English
• ISSNs: 0020-7683

Abstract

Abstract: Cracks in kerogen-rich shales and other brittle rock-like materials have a tremendous impact on their elastic properties and strength. In this paper, we investigate the effective mechanical properties of shale plates with pre-existing cracks. We employ the extended finite element method (XFEM) to investigate a pre-cracked medium with an elastic, isotropic and brittle shale matrix. We show how the mechanical properties of the orthotropic shale plates are dependent on the crack density and the standard deviation of crack angles. Both the Young's modulus and the Poisson's ratio of the cracked media exhibit a linear dependence on the standard deviation of crack angles, in contrast to the nonlinear dependence of the strength on the angle deviation. Finally, we propose mechanical models to capture the relationship between the mechanical properties and the distribution characteristics of pre-existing cracks in shales. These phenomenological models could be applied to estimate the fracking behavior of shales in engineering practice.